In this talk we present the status of self-consistent theoretical methods, to describe the ground state properties and in particular nuclear masses over the entire range of the periodic table. We discuss their advantages and their shortcomings for the description of nuclear masses as compared to earlier more phenomenological methods based on the macroscopic-microscopic approach. In particular we emphasize, that in regions close to the drip-lines one expects a softening of the nuclear surface and a reduction of the spin-orbit splitting, which leads the quenching of some shell effects. This has to be described self-consistently. As compared the non-relativistic methods, relativistic models have the advantage, that they are assumed to be more reliable in taking into account the proper isospin dependence of the spin-orbit splitting. ©1998 American Institute of Physics.